test.yml: Document ansible_local.local_facts, ansible_architecture etc

[holta]

In support of Ansible literacy for IIAB in general.

As affects situations similar to:

• use iiab fact os instead of ansible distribution iiab-admin-console#496
• Sugarizer won't start due to "Illegal instruction /usr/bin/mongod --repair --dbpath /library/dbdata/mongodb" [also reveals flaws in /etc/mongod.conf, mongodb.service & iiab-mongodb-repair-if-no-lock] #3236

[tim-moody]

could add ansible_distribution

[holta]

could add ansible_distribution

Good idea.

Caveat: after Ansible 2.6, they asked us to use ansible_facts['distribution'] instead of ansible_distribution here:

• https://docs.ansible.com/ansible/latest/user_guide/playbooks_conditionals.html#commonly-used-facts
• https://techviewleo.com/list-of-ansible-os-family-distributions-facts/ likewise recommends distribution, os_family and distribution_major_version
• https://www.reddit.com/r/ansible/comments/ooks2x/comment/h632obj/